There are many different applications for unique signatures or identifiers. For example, a unique signature can be used to uniquely identify a specific physical object within a group. One example of the use of a unique signature is a unique number that is calculated and assigned to a piece of electronic equipment. If that unique number is not recalculated correctly upon attempted operation of the electronic equipment, thereby indicating possible tampering with the equipment, then the electronic equipment is not allowed to operate. Another area of use of a unique signature is in encryption technology in which a unique encryption key is generated and stored in non-volatile random access memory.
In certain applications, particularly high security applications, it is important to prevent unauthorized access to the unique signature in order to prevent duplication or replication of the signature that can, for example, be used to gain unauthorized access to sensitive data or allow unauthorized use of equipment. In the case of current encryption technology, the encryption key is intended to be erased from memory if an unauthorized person tries to access the encryption key. However, this active erasure approach requires active power or a battery source, which is not necessarily always present. Additionally, the erasure timeline of an active erasure approach may be too long for some application environments.